1. Field of the Invention
The present invention relates to surgical anastomotic stapling devices. More particularly, the present invention relates to end to end anastomotic surgical staplers avoiding minimal constricture at the anastomosis site.
2. Background Information
Surgical staplers have been developed to assist and improve a wide variety of surgical procedures. Surgical staplers provide precision in the placement of staples as well as decrease the time of given surgical procedures. A wide variety of surgical staplers have been developed for vascular, gastric, esophageal and intestinal surgery, to name but a few. These known staplers are often used in anastomosis procedures. In performing surgical anastomotic stapling, generally the two pieces of lumen are attached by a ring of staples with a closed loop stapler. The anastomosis of the lumen may be performed in a side to side, side to end or end to end manner which describes the relative orientation of the lumen sections.
The surgical staplers for performing end to end anastomosis are generally intraluminal surgical staplers that fire a pair of staggered rings of staples. These types of surgical staplers are often referred to as EEA""s, which stands for xe2x80x9cEnd to End Anastomosisxe2x80x9d. During this procedure, a circular knife blade is used to separate tissue which is held within the circular ring. The separated tissue is then removed with the stapler so that a circular opening within the lumen is completed along the surgical stapling line.
In performing these surgical procedures with EEA""s it has become desirable to separate the anvil on which the staplers are clinched from the stapling head portion from which the staples are expelled. It has been typical in the past that the stapling head is attached to the anvil and the tissue is secured through a xe2x80x9cpurse stringedxe2x80x9d gathering of tissue.
Generally, the tissue stapled together with an EEA leaves a smaller opening than the original lumen into which the anvil and stapler head were inserted. Frequently, it is desirable to provide an anvil which can be collapsed to introduce the anvil into the body through a relatively small incision. An example of a surgical stapler having a variable diameter anvil is illustrated in U.S. Pat. No. 4,505,414 disclosing an anvil, integral with a surgical stapler, which can be collapsed and inserted through a small incision in a patient""s body and expanded outwardly after placement inside the patients body to staple the wall of an organ to the abdominal wall or an external tissue layer of the patient""s body. The anvil is not detachable from the stapler and thus cannot provide a continuous stapler line, but rather applies a broken, discontinuous line to xe2x80x9ctackxe2x80x9d the tissue in a circular line. This patent also does not provide an anvil which can be placed remotely within the body for subsequent attachment to a stapler head.
Other examples of anvils which are capable of collapsing to a reduced diameter after stapling to facilitate removal from the body are shown in U.S. Pat. Nos. 4,752,024; 4,893,622; 4,700,703 and 4,903,697. These anvils are introduced into the body through a relatively large incision.
U.S. Pat. No. 5,239,639 also shows a collapsible anvil assembly and applicator instrument for a surgical stapler apparatus.
The retractable anvil EEA""s discussed above do not address the fundamental problem of the constricture point formed after luminal anastomosis. These prior art devices simply address the problem of post operative tool removal.
It is the object of the present invention to avoid the drawbacks of the prior art by avoiding the minimal constriction formed at luminal anastomotic sites using anastomotic staplers (i.e., EEA""s). It is a further object of the present invention to provide anastomotic staplers which are easy to manufacture and utilize. A further object of the present invention is to provide both intraluminal anastomotic end to end staplers and extraluminal anastomotic end to end staplers.
The above objects are achieved with the anastomotic device according to the present invention. The anastomotic device according to the present invention is a surgical stapler that will form an anastomosis between existing lumen sections in an end to end alignment forming the anastomosis site with a minimal diameter generally equal to or greater than the normal inner diameter of the anastomized lumen sections, with the lumen sections in a normal relaxed condition. The anastomotic device of the present invention will preferably utilize conventional staples formed in a pair of offset annular arrays of staples to couple the end of a first lumen section to the end of a second lumen section.
A first embodiment of the present invention forms the anastomotic device as an intraluminal end to end surgical stapler. The intraluminal surgical stapler fires staples, or other fastening devices, from a stapling head to an adjacent anvil. In accordance with the present invention, both the head and the anvil can be moved from a retracted position having a first relative diameter to an expanded position of a second larger diameter. The expansion of both the head and the anvil allows the anastomotic device to be positioned in the lumen to be attached with minimal interference and then expanded to an enlarged firing position, wherein when fired the anastomotic ring formed by the array of staples is positioned at a diameter preferably at least as large as the minimum diameter of the adjacent lumen sections. After firing, the head and anvil of the stapler of present invention can both be retracted to allow for easy withdrawal of the stapler from the anastomized lumen.
In one embodiment of the present invention, the head will be formed of a plurality of wedge-shaped arc segments which move radially and align in an expanded position to form the annular head. The arc segments may be in the form of inner wedge-shaped segments moved by an actuator and outer segments guided by the inner wedge-shaped segments. The wedge-shaped segments may be moved into the expanded or retracted positions by being coupled to the actuator in the form of axially movable wedges controlled by the user.
Another embodiment of the present invention will form the annular head as a plurality of arc segments that slide together with the segments formed in an overlapped position in the retracted state and rotate into contracted and expanded positions. A further embodiment of the present invention will hinge various arc segments together to allow the segments to pivot between a retracted position of a minimal diameter and an expanded position forming the annular head ready for firing.
Each individual arc segment of the head portion will include staples which combine to form the array of staples in the expanded position. One key aspect of the present invention is that each arc segment has a separate firing mechanism as well as a knife actuating mechanism independently associated with each segment. Each segment will have an arcuate knife portion which will combine and overlap with the knife portions of adjacent segments to form a continuous annular knife arrangement when the head is in the expanded position. In this manner, the knife portions and staples of each individual segment will combine to form the dual stapling array and annular knife well-known to those skilled in the art (except of a larger diameter relative to the body of the stapler). The firing mechanism of each individual segment is additionally coupled to the controller of the stapler in a manner which accommodates movement of the individual segments between the retracted and expanded positions. This construction of the segments allows for the segments to be formed in the hinged arrangements, spirally attached arrangements or wedge arrangements discussed above. Many other possible relatively movable combinations may be constructed with the individual segment construction of the stapler of the present invention.
Another aspect of the present invention is to form an external end to end anastomotic surgical stapler. The external stapler according to the present invention is designed to clamp around lumen sections to be attached. The extraluminal stapler according to the present invention is designed to form an anastomizing ring of sutures external to the connected lumen sections. The external stapler according to the present invention forms a pair of annular arrays of staples around an outwardly extending flange of the connected lumen sections.
In one embodiment according to the present invention, the extraluminal stapler is formed of two opposed stapler units with each stapler unit formed of two halves hinged together. The extraluminal stapler will include a mechanism for pulling the lumen to be attached around the stapling face of each stapling unit. The extraluminal stapler according to the present invention will additionally include a mechanism for aligning the stapling head and anvil portions of the opposed stapling units with each other as well as a firing mechanism for firing the arrays of staples in the stapling units. One embodiment of the present invention will form each stapling unit as an anvil and head portion hinged together which couples with an adjacent hinged anvil and head portion of the opposed stapling unit.
The present invention would be particularly applicable for bowel resections as will be understood by those of ordinary skill in the art, but is not intended to be limited thereto. It can be used in many other applications such as, but not limited to, vascular anastomosis, gastrointestinal anastomosis, esophageal anastomosis and essentially any hollow lumen within the body. Further, the specific embodiments of the invention include a variety of unique features that can be incorporated separately or in various combinations into other stapling and surgical devices for improving those devices.
One advantage of the present invention is a minimally invasive surgical stapler that will assist in stapler placement because the diameter of the stapler (i.e. the largest diameter portion, specifically the head and anvil of the stapler) is smaller during insertion and retraction than at firing.
Another advantage of the present invention is having a closed loop EEA stapler with the trimming knife formed by individual knife segments. This feature of the present invention may be utilized for firing the knife segments individually, or in a given sequence, or simultaneously (as utilized in the illustrated embodiments of the present invention.
Another feature of the present invention is the accommodation of multiple anvil and multiple head controls in a surgical stapler. One present illustrated embodiments provide separate controls for expansion/retraction of the anvil and for axial movement of the anvil. This illustrated embodiment further provides independent control for expansion/retraction of the head and for firing of the knife blade and staples. This system of multiple independent control may be modified to perform a variety of separate control features for the anvil and head portions of an EEA stapler.
Another feature of the present invention is the provision of an EEA stapler with a staple and knife firing mechanism that accommodates relative motion of the head portion containing the staples and the firing mechanism.
Another feature of the present invention is the provision of an alignment mechanism that aligns and locks the anvil and head portion together prior to the firing of the staples or the knife.
Another feature of the present invention is the provision of a closed loop surgical stapler for end to end anastomosis in which the stapler extends around the outside of the lumen portions being anastomised.
These and other advantages of the present invention will be clarified in reviewing the detailed description of the preferred embodiments taken together with the attached figures wherein like reference numerals represent like elements throughout.